I propose that we support a switch expression as a statement expression when every arm's expression is also a statement expression. No common type among the arms is required when used as a statement expression.

void M(bool c, ref int x, ref string s)
{
    c switch { true => x = 1, false => s = null };
}

Meeting notes

https://github.com/dotnet/csharplang/blob/main/meetings/2022/LDM-2022-08-31.md#switch-expression-as-a-statement